I like all of them, unfortunately. They're delicious, but that's mostly because of the Monosodium Glutimate (MSG) they contain, which, by the way, is an excitatory neurotoxin, which essentially makes them stimulating and addictive.
I haven't had Cheetos in years since I gave up a lot of junk food, but I really liked the Flamin' Hot Cheetos when I was a kid. My vote goes to that.
I didn't know they made Xxtra Flamin' Hot Cheetos or Jalape?o Cheetos until now. Now that I know they exist and since I haven't had them for so long, I'm kind of interested in picking some up sometime soon to try them.
They only really existed here in the late 90's/early 2000's, then I believe they stopped selling them altogether here. They may still exist in a few stores somewhere, but I've not seen them since I was like 13.
If I remember correctly, they were pretty much just Wotsits, but not as good.